1. Field of the Invention
The present invention relates to a weft processing apparatus for guiding the leading end of a weft fed from a weft supply source in the form of a cheese to a weft winding type weft length-sizing and reserving apparatus when a weft feed failure such as breakage of the weft occurs between the weft cheese and the weft length-measuring and reserving apparatus or when a weft of a new cheese is to be used upon exhaustion of the weft cheese used till then.
2. Prior Art
A weft processing apparatus of the type mentioned above is disclosed, for example, in Japanese Laid-Open Patent Application No. 264949/1988 (JP-A-63-264949). In the disclosed apparatus, a suction guide tube of a conical configuration is set at a suction position in the vicinity of the peripheral surface of a weft cheese for drawing out by suction the leading end of a weft from the weft cheese and is then displaced to a stand-by position far away from the weft cheese, wherein the leading end of the weft being held under suction is inserted into an introducing port of the winding type weft length-measuring and reserving apparatus. The leading end of the weft sucked by the suction guide tube and positioned at the introducing port is then inserted into the introducing port under the sucking action thereof to be thereby threaded into and through the weft length-measuring and reserving apparatus. In this manner, the suction guide tube is changed over between the sucking position where it encloses the weft cheese and the stand-by position far away from the weft cheese.
Since the prior art apparatus is of such a structure that the drawing-out of the leading end of the weft from the cheese and the introduction of the weft drawn out to the introducing port of the weft length-measuring and reserving apparatus are performed by using one and the same suction guide tube, the latter is restricted in respect to the configuration size and the location for installation and thus suffers from a problem that the freedom in design is seriously limited. For example, the sucking position of the suction guide tube has to be set so as to match with the full bobbin weft cheese. Consequently, when failure occurs in the course of feeding a weft under the condition that the diameter of the weft cheese has been decreased smaller than that of the full bobbin cheese, the sucking position of the suction guide tube will no longer be optimal for the weft cheese of concern. As a result, the sucking action of the suction guide tube becomes lowered particularly when the weft cheese has been reduced in the diameter, giving rise to the unwanted possibility that the drawing-out of the leading end of the weft from the weft cheese results in failure. Also, the structure of the apparatus is inevitably more complicated because of the necessity for moving the suction guide tube toward the weft length-measuring and reserving apparatus in order to introduce the weft leading end into the introducing port of the weft length-measuring and reserving apparatus.
Further, it is noted that the leading end of the weft sucked by the suction guide tube lies in a linear form. In this conjunction, it is clear that the area presented by the weft of a linear form and subjected to the action of a transporting air flow such as suction or blowing is very small. Consequently, displacement of the linear weft to another place or location under the action of the transporting air flow lacks in reliability.